US 11,707,243 B2
Scatter and random coincidence rejection
Liang Cai, Vernon Hills, IL (US); Wenyuan Qi, Vernon Hills, IL (US); Xiaochun Lai, Vernon Hills, IL (US); and Peng Peng, Vernon Hills, IL (US)
Assigned to CANON MEDICAL SYSTEMS CORPORATION, Otawara (JP)
Filed by CANON MEDICAL SYSTEMS CORPORATION, Otawara (JP)
Filed on Apr. 14, 2021, as Appl. No. 17/230,499.
Prior Publication US 2022/0330907 A1, Oct. 20, 2022
Int. Cl. A61B 6/00 (2006.01); G01T 1/24 (2006.01); G01T 1/172 (2006.01); A61B 6/03 (2006.01)
CPC A61B 6/5205 (2013.01) [A61B 6/037 (2013.01); G01T 1/172 (2013.01); G01T 1/248 (2013.01); G01T 1/249 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A nuclear medical diagnostic apparatus, comprising:
first and second gamma ray detectors for detecting first and second annihilation gamma rays, respectively;
processing circuitry configured to
identify a possible coincidence event between the first gamma ray detector and the second gamma ray detector;
estimate a range of possible flight directions for the first annihilation gamma ray detected by the first gamma ray detector based on a Compton scatter event, which is detected by the first gamma ray detector, wherein the possible coincidence event includes the Compton scatter event detected by the first gamma ray detector;
determine whether the second gamma ray detector is located within the estimated range of possible flight directions; and
count the possible coincidence event as a true coincidence event when determining that the second gamma ray detector is located within the range of possible flight directions, and not count the possible coincidence event as a true coincidence event when determining that the second gamma ray detector is not located within the range of possible flight directions.